1. Field of the Invention
The present invention relates generally to ink cartridges configured to be used in an image recording apparatus. More specifically, the present invention is directed towards ink cartridges comprising an ink supply portion and an ink holding portion formed at the ink supply portion.
2. Description of Related Art
A known ink-jet image recording apparatus has a recording head and an ink supply device configured to supply ink to the recording head. A known ink cartridge is configured to be mounted to the ink supply device. The known ink cartridge has a case, and the case has an ink chamber formed therein. The ink chamber is configured to store ink therein. The known ink cartridge also has an ink supply portion, and ink is supplied from an interior of the ink chamber to an exterior of the ink chamber via the ink supply portion. When the known ink cartridge is mounted to the ink supply device, ink stored in the ink chamber is supplied to the recording head via the ink supply portion. The recording head is configured to selectively eject ink toward a sheet of paper, such that an image is recorded on the sheet.
Another known ink cartridge, such as the ink cartridge described in JP-A-2007-144808, has an ink supply portion having a tube-shaped wall extending from a particular face of a case of the ink cartridge. The ink supply portion also has an elastic member positioned at the end of the tube-shaped wall. The elastic member has an opening formed therein. When the another known ink cartridge is mounted to the ink supply device, an ink tube of the ink supply device is inserted into the opening of the elastic member. When this occurs, the elastic member is configured to elastically deform and to contact the outer surface of the ink tube liquid-tightly. The ink supply portion also has a cap, and the elastic member is sandwiched between the end of the tube-shaped wall and the cap while the elastic member is elastically deformed. The cap has an end wall having an opening formed therein, and a peripheral wall covering a portion of the elastic member and a portion of the tube-shaped wall. When the another known ink cartridge is mounted to the ink supply device, the ink tube is inserted into the opening of the cap and then into the opening of the elastic member. The ink supply portion further has a valve element and a spring positioned in the tube-shaped wall. The spring biases the valve element toward the elastic member. When the another known ink cartridge is not mounted to the ink supply device, the valve element contacts the elastic member and covers the opening of the elastic member while being biased by the spring. When the ink tube of the ink supply device is inserted into the opening of the elastic member, the ink tube contacts and pushes the valve element against the biasing force of the spring, such that the valve element moves away from the elastic member. As such, ink is supplied from the interior of the ink chamber to the exterior of the ink chamber via the ink tube.
When the another known ink cartridge is mounted to and removed from the ink supply device, ink may leak from the ink supply portion or the ink tube, or both, and the leaked ink may adhere to the outer surface of the cap. When the another known ink cartridge is repeatedly mounted to and removed from the ink supply device, such leaked ink may drip from the ink cartridge.